Apparatus for preparing highly uniform solutions for the manufacture of artificial products



Sept. 13, 1932.,

A. KAMPF ET AL ,877,337 APPARATUS FOR PREPARING HIGHLY UNIFORM SOLUTIONSFOR THE MANUFACTURE OF ARTIFICIAL PRODUCTS Filed Match 25, 1950 t [asPatented Sept. 13, 1932 ADOLF ,KEMPF, or pnssA -zI Ie -mminarnnnn nAGER;or woman, GERMANY, AssIeNoRs TO I. e. ramarmrunpsgrem l K'rrn1v EsELLscH-AFT, or

v R NKJMRm-o -r s mllv, G RMANY APPARATUS FOR PREPARING HIGHLY nmrormsoLu'r-rons-roa THE MANUFACTURE or ARTIFICIAL rnonucrs' I a v r aApplication filed March '25, 1930, Seria1 No 5438 870, and-intfierinany:March 27,1529.

Our present invention relates to a process of preparing spinningsolutions asfused in themanufacture of artificial threads, fi-

.bers or films and more particularly tosuch a process carried out on alarge scalein which the said solutions prepared in a continuous mannerand in a plurality of dissolving vessels are filtered, deaerated andmade ready for the coagulation process. Anotherobject of ourinvention isa device for carrying out the saidprocess.

- Thelinjuries to which spinning solutions,

especially viscose, arev exposed when forup of single batches ofspinning solutions Ly does not lead to uniform products even if the 7use of compressed air or the like (is avoided,

as far as this is practically possible, during the manufacturer of thespinning solution. 7 -'-Due to the inevitable changes of the numerousimportant factors which give rise to constant- -ly occurring greater orsmaller difierences be-l tween the single batches, it is diificult toobtain auniform end-product and these difliculties rise whenworking-up aviscose solution to be spun wlth as low a degree ofripeness as possible.

By our present invention thesedisad vantages are avoided by making useessentially of two expedients.

(1). The batches of viscose dissolved more orless at the same time inseveral dissolving- -"vessels, are not filtered individually eachthrough a separate filter but all of the spin-r ning solutions, readyfor filtration, are l; pumped iniknownmanner without using com- 1pressed air, into a collecting piping which delivers'the solution to asuitable number of filters presses-arranged in, parallel, Pref- .50 -vided in excess ofthenumber requ red for erably, atleastlone filter pressshould be promon ducttwhere they are combined into a sinl s ream.ln-this manner, the iggle batches 1 ;(-2). Thefiltered spinning solutionis not r a tedashithe e J f llalkin bafhes each of which is ,chargedinto difierent collecting v ss ls:fromwh chtmsqlu ic is d aw req ire 1deae ati aii further treatamen-b.1 12 (it is sq t n q n du into a icmmqnlhemc eni i or equ i selfrem whichattheiop s e i With- F w 117wn,,.azcanthnaau yan I 1 L un a manner as poss1ble,;to the spinningdevice.

., Thesai eqommv rvs e rv S t al .urpqse I .Itzse v o ieompen at th a o-;ah e irre u arit e -flame r o pp y of 1:fi i edpinl i sb utionto he v(b The-spinni g s i t o s freed f s in: th homqgenizin vess T i p nn ng;oluti n s c nt n s y subje t d -.-t. a tm chanical ag t n dur g itspassage through =the vesseL i "For t purpose in ic ted. under )v the esl. 5 s is itab x dimensioned, fiQrIB P i g y; with t @q anti ypf P i iql whichfis to pass through it.

x 'With;respect;t0 the feature of the process 1 outlined nd r (6) torieg; the sp nn 7 solution irom; gas on its way through a the .homqgeni ng-.%v sse ,;t ol ow P r Eaular ,measuresjmaytba a opted.

oiSinCetheSPinning.YSQ tiQI is e Stirred in the vesseland withdrawnfromthe outlet to; h spinaing machi by'l an f. ap p it ay h ppen thatlrzm yi e d awn r a the stuffing boxes andthe'bearingsof the drivi gzandtubular shaft and absorbedby, the

spinning solution kept ,under a-vacuum.

In order to avoidithis danger, the vessel is prov ded-With. a ver ical tbul eXteIisiOn alrea y tail ate a; i 1 e te ii the. ng operation. i

pieceof such a height that at the lower part of the vesselat which partthe stirring mechanism is arrangedthe reduced pressure is approximatelycompensated by the hydrostatic pressure of the'column'of liquidin thetube. When operating, for instance, under. a reduced pressure of 150 mm.of mercury,

. the pressure due to the head of the spinning solution must correspondwith the pressure of about 600 mm. of mercury for viscose,

having a specific gravity off l-.15- this would require a tubularportion having a height of about 7 meters.

In order that the spinning solution enteringthe vessel, may remaintherein for the period necessary for a complete removal ofga's,the

vessel bears on the tubular extension piec'e a funnel-shaped or conicalhead plece. Now,

at'the upper rim of the funnel, which may have a diameter of severalmeters, the current of filtered spinning; solution is Poured, by

- 'means of a rotary distributing pipe,"onto the not mountedhorizontally but somewhat inclined to the discharge pipe.

inner surface of the funnel in such a rate, that the time during whichthe spinning solutlon flows downwards in a thin layer over the innerwall of the funnel issuflicient for completely liberating thespinningsolutionfrom air or gas; if required, there may be provided inaddition to the rotary distributingplpe a scraper which is caused totravel overthe conical surface, thus preventing viscose from remainingon the wall of the funnel'for too long a period. It is a question of thequantities produced whether between the tubular andthe conical member awidened cylindrical partis provided which forms the real homogenizingroom of the vessel.

Referring to purpose v(c), the vessel shall further serve formechanically agitating the spinning solution. For this purpose, thelower part of the vessel is provided with a longitudinal shaftcarrying-mixingarms', so that the spinning liquid flowing through thelower part of the vessel is continuously; mixed by stirring. Preferablythe said lower part is In working-up anunripened viscose, it isdesirable to use a homogenizing vessel which is not excessively large,in' order that theviscose may not remaln for too long a per od 1n thevessel and ripen in an undesired degree. In using ripened viscose, thebuffer vessel may be of a correspondingly larger size. At the, outlet ofthe buifer vessel the spinning li'quid is received, as above stated, bya pump for- 1 mixing of the spinning liquid.

warding it in known manner'tothe spinning machine.

Anessential feature of the invention conand f sists in. thecontinuous'remo'val of The annexed drawing illustrates diagrammaticallybyway of'example a device suitable for executing the invention.

The spinning solution prepared in the, dis- Levies? solving vessels 1flows under its own weight through the common pipe 2 to the eccentricpump 3 by which the crude spinning solution is forwarded through thecommon connecting pipe '5'to the filter presses 6. In order that thefiltration may be conductedunder constant pressure, a return-flow pipetis providedby which anyliquid deliverel by the e'ccentric pump 3 inexcess of the quantity capable of passing through the filter presses, isreturned to the sucking side of the pump. he filtrates from the severalpresses are combined in the common pipe 7 and-flow through a rotaryswivel-tube 9 driven at 10, whichdelivers the solution to the upperconical portion of the surface of an exhausted equalizing vessel 8. Thesolution flows in the form of a thin layer downwardly on the inner wallof the funnel, is removed therefrom by. a

scraper 21 and collects in the cylindrical part the homogenizing vessel8 bears a branch 2O through which the air is exhausted.

The spinning solution is slowly but continuously mixed by means of astirring de vice 15 in an extension 1 1' of the portion 13, slightlyinclined to the horizontal. From the lowest point of theextension 14:,the spinning solution passes the feeding eccentric pump;

16 having a return flow-pipe 17 provided with a' pressure regulator, andis forwarded under ing to the spinning machines. V v It is recommendableto provide all the parts 11, 13 and 14 of the buffer Vessel 8 and,if

' required, also the feed pumps 8 and 16 with .a jacket as indicated at19 for the purpose of maintaining the solution in the vesseliat aconstant temperature.

Obviously, our present invention is not limited to the foregoingstatements. 7

. As known in the art, spinningsolutions may also be deaerated, forinstance, by admixing volatile solvents and by evaporating the same.

In this case, it is preferable to operate without evacuation of thehomogenizing vessel, but to heat feebly the wall of its conical part.

Numerous other embodiments are possible and we contemplate as includedwithin our invention all such modifications and equiva *lents as-fallwithin the scopeof the appended claims. What we claimisz-s i r I I 1.Ina machine for producing highlyuni form solutions for the manufactureof artificial products consisting of cellulose derivaconstant pressurethrough the piping 181eadtives a homogenizing and deaerating meanscomprisinga vesselwith a furinel-shapedw head part, a circularly.rotary;.-.swivel tube adapted to distribute the spinning solution in theform of a thin layer on the funnelshaped head part, means to evacuatethe said vessel, a cylindrical collecting part, a tubular 5 extensionpiece of substantial height, a slightly inclined almost horizontallymounted receptacle and in the latter a mixing device.

2. In a machine for producing highly uniform solutions for themanufacture of artificial products consistingof cellulose derivatives ahomogenizing and deaerating means comprising a vessel with afunnel-shaped head part, a circularly rotary swivel-tube adapted todistribute the spinning solution in the form of a thin layer on thefunnel-shaped head part, means to evacuate the said vessel, acylindrical collecting part, a tubular exten- V sion piece of a heightbalancing when filled with spinning solution by the hydrostatic 29pressure of the latter the action of the vacuum on the parts mounted onits lower end, a slightly inclined almost horizontally mountedreceptacle and in the latter a mixing dee vlce.

3. A machine for producing highly uniform solutions for the manufactureof artificial products consisting of a cellulose derivative comprising aplurality of dissolving vessels, a pump provided with a return flux,

30 a plurality of filter presses, a common piping. through which thecontents of the dissolving vessels is forwarded to the pump and from thepump to a plurality of filter presses, a second common pipe collectingthe filtrates of the different filter presses, a homogenizing anddeaerating means comprising a vesfisel provided with a funnel-shapedhead part, a circularly rotary swivel-tube adapted to distribute thespinning solution in the form of a thin layer on the funnel-shaped headpart, means to evacute the said vessel, a cylindrical collecting part, atubular extension piece of a height balancing when filled with spinningsolution by the hydrostatic pressure of the latter the actionof thevacuum on the parts mounted on its lower end, a slightly inclined almosthorizontally mounted receptacle and in the latter a mixing device, and asecond pump provided with a return flow and adapted to forward thesolution under constant pressure to the spinning machine. 7

In testimony whereof, we afiix our signatures.

ADOLF' KAMPF. ARNULF HAGER.

